Mercury-vapor rectifier



NOV. 27, 1934. s E s MERCURY VAPOR RECTIFIER Filed May :51, 1930 u T :v 0 Y \UM.

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INVENTOR Alfred Siemens ATTORNEY Patented Nov. 27, 1934 A UNITEDST ES MERCURY-VAPOR'REGTIFIER I Alfred Siemens, Berlin-Charlottenburg, Germany,

assignor to Westinghouse Electric & Manufacturing Company, a corporation of Pennsylvania Application May 31, 1930, SerialNo. 458,007 In Germany June 11, 1929 4 Claims.

My invention relates to mercury-vapor rectifiers and particularly to such devices having ring coolers to condense the vapors rising from the cathodes.

5 There has been some difliculty in maintaining a reduced vapor pressure in mercury-vapor rectifiers. A vapor pressure that is too high is believed to be responsible for at least a part of the troubles, such as back-fire or short-circuiting of rectifiers.

In order to introduce sufiicient cooling surface into a mercury-vapor rectifier, it has been common practice to make the tank of unnecessarily large dimensions and to separate the anodes to greater and still greater distances. This has increased the arc length until the arc drop has become a source of appreciable loss in such apparatus.

It is an object of my invention to provide a rectifier having a large cooling surface but of small dimensions to provide the shortest possible arc length.

It is a further object of my invention to so I arrange the cooling surfaces in my rectifier that 25 the vapor pressure in the vicinity of the anode will be a minimum.

Other objects and advantages of my invention will be apparent from the following detailed description, taken in connection with the accompanying drawing, in which the single figure is a sectional elevation of a rectifier embodying my invention.

The apparatus disclosed in the drawing comprises a metal tank 1 having a plurality of anodes 2 therein. In the bottom of the tank, is a mercury cathode 3 insulated from the main portion of the tank by any suitable insulating body 4. Disposed in the central portion of the tank is a plurality of ring coolers 5, which are spaced from the top and from the bottom of the tank in such manner as to provide a central preliminary condensing chamber 6 within the anode circle.

A second set of ring coolers 10 is provided near the outer periphery of the tank. The outer ring coolers, in conjunction with the chilled wall of the tank, provide a secondary or final condensing chamber 11. The ring coolers 10 are preferably spaced a greater distance from the top of the tank than are the ring coolers 5.

In order to properly exclude mercury vapor from the space between the inner and the outer ring coolers, a sloping cover 14 is attached to the outermost of the ring coolers forming the preliminary condensing chamber. The sloping cover 14 extends across the anode space to the vicinity of the outer ring coolers and is provided with openings through which the anode stems may extend, these openings being provided with flanges 15 to exclude condensed mercury from the immediate vicinity of the anodes.

In operation, mercury vapor, rising from the cathode 3, will pass into the preliminary condensing chamber 6 and be pre-cooled or partially condensed by the coolers 5. Such vapor as is not condensed will pass through the space between the top of the ring coolers and the top of the tank, pass over the cover 14 into the final condensing chamber 11, where any remaining mercury vapor will be condensed by the ring coolers 10. In this manner, very little mercury vapor will be allowed to enter the anode space, since the vapor will be condensed and find its way to the bottom of the tank and thence to the cathode cup.

By providing a large cooling surface in the tank, it is possible to reduce the diameter of the anode circle to an appreciable extent and thereby reduce the arc length and, consequently, the arcdrop losses in the rectifier. Also, my novel structure reduces the vapor pressure in the anode space and avoids the most serious danger of backfiring.

I do not desire to restrict myself to the specific embodiment of my invention herein shown and described, since it is evident that it may be changed and modified without departing from the spirit and scope of my invention, as defined in the appended claims.

I claim as my invention:

1. A mercury-arc rectifier comprising a metal tank, a plurality of anodes therein, a mercury cathode in said tank, a condensing chamber in the central portion of said tank, said chamber being so disposed as to receive the vapor rising from the cathode, an anode chamber outside of the central condensing chamber, a second condensing chamber surrounding the anode chamber, and means extending from said central chamber across the anode chamber for preventing vapor from entering the anode chamber from the top.

2. A mercury-arc rectifier comprising a metal tank, a plurality of anodes in said tank, a vaporizable cathode in said tank, a plurality of ring coolers forming a condensing chamber in the central portion of the tank, said ring coolers being spaced from the top and the bottom of the tank, a plurality of ring coolers near the periphery of said tank, said second mentioned ring coolers forming a second condensing chamber, and

4. A mercury-arc rectifier comprising a metal tank, a vaporizable cathode in said tank, a plu-' rality of annular cooling elements forming a preliminary condensing chamber, said elements being positioned above the cathode and spaced from the top and the bottom of the tank, a plurality of cooling members near the outer periphery of the tank forming a final condensing chamber, said inner and outer members having an anode space between them, a plurality of anodes extending into said anode space, and a cover for said anode space.

ALFRED SIEMENS. 

